+ * Rescale a 64-bit integer by 2 rational numbers.
+ */
+int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) av_const;
+
+/**
+ * Rescale a 64-bit integer by 2 rational numbers with specified rounding.
+ */
+int64_t av_rescale_q_rnd(int64_t a, AVRational bq, AVRational cq,
+ enum AVRounding) av_const;
+
+/**
+ * Compare 2 timestamps each in its own timebases.
+ * The result of the function is undefined if one of the timestamps
+ * is outside the int64_t range when represented in the others timebase.
+ * @return -1 if ts_a is before ts_b, 1 if ts_a is after ts_b or 0 if they represent the same position
+ */
+int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b);
+
+/**
+ * Compare 2 integers modulo mod.
+ * That is we compare integers a and b for which only the least
+ * significant log2(mod) bits are known.
+ *
+ * @param mod must be a power of 2
+ * @return a negative value if a is smaller than b
+ * a positive value if a is greater than b
+ * 0 if a equals b